Inductive control device



Patented Jan. 12, 1932 DANIEL HERBERT SCHWEYER, EASTON, PENNSYLVANIA INDUCTIVE CONTROL DEVICE Application filed March 30, 1925. Serial No. 19,527.

The present invention relates to inductive control means intended especially for use in automatic train control, and aims to provide a novel and improved inductor to be carried 6 by a locomotive, car or other vehicle and adapted" to be influenced inductively when passing an inert iron mass or armature provided for that purpose, when passing said mass of iron or armature, to produce an in- 10 itiating or actuating effect, such as, for htaining a danger indication or condition in the vehicle.

Another object is the provision of an inductive signal-impulse receiving device includ- 15 ing an inductor of novel and simple construction having a constantly excited coil or winding for exciting or energizing the inductor, and having an impulse Winding or coil controlling an electromagnet or other translating means for obtaining a predeterminedindication or condition when the device passes an inert armature, such as a mass or body of iron.

WVith the foregoing and other objects in view, which will be apparent as the description proceeds, the invention resides in the construction and arrangement of parts, as

hereinafter described and claimed, it being understood that changes oanbe made Within 30 the scope of what is claimed, without departing from the spirit of the invention.

The invention is illustrated in the accompanying drawings, wherein- Figure 1 is a diagrammatical view of one form of apparatus embodying the invention, using alternating current and a choke coil. or winding on the armature.

Fig.2 is a diagrammatical view of another form of alternating current apparatus embodying the invention, without the choke coil on the armature.

Fig. 3 is a diagrammatical View illustrating a direct current apparatus embodying the invention, and using a choke coil on the armature.

Referring to Fig. 1, the inductor, which is carried by a locomotive, car, or other vehicle, is indicated at 7, and has a core of iron or other magnetic material provided with the three legs 8, 9 and 10, with the leg 9 located intermediate the legs 8 and 10, and said core has the yokes 11 and 12 connecting the le 9 with the legs 8 and 10, respectively. he intermediate leg 9 is common to both yokes 11 and 12. The legs 9 and have pole portions 13 extendingtoward one another to provide a relatively short air gap between the legs 9 and 10, and the leg 8 has a pole portion 14 extending away from the leg 9, so that the fir gap between the legs 8 and 9 is relatively ong.

V The inductor 7 comprises a constantly energized electromagnet or transformer. Thus, an exciting winding or coil 15 embraces the leg 9 of the core and is connected to the alternating or pulsating current generator 16 to establish an alternating magnetic flux in the core. An impulse winding or coil 17 embraces the yoke 12 and is connected in circuit with an electromagnet 18 or other translating means controlling an armature, switch or other indicating or control member 19.

The inductor is movable past an armature 20 on the track or adjacent to the path of movement of the inductor, which armature comprises a body or mass of iron or other magnetic material, which is of suitable size to bridge the air gaps of the inductor core with a suitable clearance between the inductor and armature. A choke coil or winding 21 embraces the intermediate portion of the armature 20 and is, under clear trafiic conditions, in a circuit of low resistance including the switch 22 under the control of an electromagnet 23. Said electromagnet or other control means may be included in a circuit of the wayside signalsystem, or may be con trolled otherwise, so that the magnet is energized under clear track conditions to hold the switch 22 closed, the magnet being deenergized, under dangerous track conditions, to permit the switch 22 to drop open. It will be apparent that one of the arniatures 20 may be located near each semaphore of the wayside signal system, so that the switch 22 is controlled, either electrically or mechanical- 1y, according to the position of the semaphore arm, as well known in the art, it being apparent that the switch 22 may be controlled manually, electrically, pneumatically or me- 790 roll chanically to close the circuit of the winding r coil 21 for clear conditions, and to open the'circuit for danger or emergency conditions. 7 g

In operation, when the inductor is away from the armature 20, the magnetic flux created by the constantly energized winding 15 will flow in the core, and although the winding 17 has a choking effect or resistance in one )art'of the-core, the large air gap between the legs8 and9of the other part of the core will provide a counter impedance. Consequently, the short air gap between the legs 9 and 10' will permitsufficient magnetic flux to flow in the magnetic circuit of the windings and 17 to energize the winding 17 and'magnet 18 so thatthe armature or switch .19 is held in raised or closed position. The magneticcircuit of the windings15 and 17 includes that part of the core comprising'jthe arms 9 and 10, yoke 12, pole portions '13 and the short air gap between said pole portions. The other part of the core including the legs 8 and 9, yoke 11, pole portion 14, pole portions 13 of the leg 9, andthelong airgap, comprises a second magnetic circuit for the flux created by-the winding 15. However, the longair gap of the second magnetic circuit provides sufficient impedance in said magnetic circuit'to make up for the impedance in the first magnetic circuit due to the winding 17 and the short airgap between the pole portions 13 offers less impedance than the longair gap of the second magnetic circuit. The transformer action will therefore result inathe winding 17 being energized-by inducticn, from the winding 15, the winding15 being the primary of *the transformer and the winding .17 the secondary.

\Vhen the inductor passes ininductive relation adjacent to the armature 20, with the switch 22 open, so that the coil or winding 21 is ineii'Tectiva-the armature will be inert. Now,the armature or mass of iron 20 bridges both air gaps ofthe inductor core,-with suitable clearance between the core and armature, and this disturbs the normal magnetic equilibrium-of the inductor; It will be noted that the air gaps of'the two magnetic circuits of the inductor are now the same,the pole portions and 14 being-substantially equal distances from the armature. Consequently, the air gap impedances-of thetwo magnetic circuits are-the-samei,ethe magnet-1c flux in each circuit flowing through the armature 20 as the path of least resistance between the pole portions. Therefore, the impedances between the pole portions of the two magnetic circuits being substantiallyequal, the winding 17-. now acts as a choke coil, so that the impedance in the first magnetic circuit is greater than the imped-ance in the second magnetic circuit, and

the magnetic flux has a freepath through the second magnetic circuit including the legs .7- and 9, yoke 11 and armature 20 with air gaps between the armature and said legs 8 and 9. The greater portion of the magnetic flux will now flow through the said second magnetic circuit thereby magnetically shunting the winding or coil 17 so as to deprive it of magnetic energy. This will deenergize the magnet 18 suificiently to permit the an mature 19 to drop. Same will either indicate a danger or corresponding condition, or may be used for controlling the movement of a vehicle by applying the brakes, or the like, as wellknown in the art.

lVhen the inductor leaves the armature, normal conditions will be restored in the inductor device, so that the magnet 18 will be reenergized, butthe effect obtained by the dropping of the switch or armature 19 may be continued through the block. Thus, the switch or armature 19 may drop out of the influence of the magnet 19 so as not to be restored excepting manuallyor byother means (not shown). 7 When the switch 22 is closed during the passage of the inductor adjacent to the armature, the choke oil 21will be effective so as to impede the flow of magnetic flux through the armature 20. The result will be substantially the same as if the armature were not present. Thus, the flow of magnetic flux from the core through the armature, especially in the second magnetic circuit, is impeded by the choking or bucking action of the coil or winding 21. Consequently, the armature does not oifer a decrease in i-mpedancein the second magnetic circuit of the inductor, so that suiiicient flux flows in the first magnetic circuit to keep the winding 17 and magnet 18 energized, as seen in Fig. 1.

Fig. 2 illustrates an inductor 7a having the same core as shown in Fig. 1, and exciting windings or coils 15a embrace the legs 8 and 9 and are connected to the alternating or pulsating current generator 16. The impulse winding or coil17a embraces the leg 10 and is connected in circuit with the electromagnet or translating means 18. There is also shown-an armature or mass of iron 20a which does not have a choke coil thereon.

When the inductor is away from the armature 20a, the windings 15a create magnetic flux in the second magnetic circuit'including the arms 8 and 9, yoke 11 and long air gap between said arms, and the magnetic flux created by the winding 15a on the arm 9 will flow through the first magnetic circuit including the arms 9 and 10, yoke 12 and short air gap between the pole portions 13, it being apparent from the foregoing, that the short air gap of the first magnetic circuit will decrease the impedance of the first magnetic circuit, as compared with the impedance of the long air gap in the second magnetic circuit, so that the winding 174: will be energized. Thus, the combined impedance of the short air gap and winding 17 a of the first magnetic circuit is less than the impedance of the long air. gap of the second magnetic circuit. However, when the inductor passes close to the armature a, the impedance of the air gaps are now equalized, said armature bridging both air gaps, with equal clearances between the pole portions and armature. Consequently, the armature shunts the first magnetic circuit so that the greater portion of the magnetic flux will now flow through the second magnetic circuit, thereby depriving the winding 17 of its energy so that the magnet 18' is deenergized and the switch or armature 19 released. If the armature 20a is fixed. this effect will be obtained whenever passing the armature or a similar one and other suitable means would have to be provided for nullifying the initiating'or actuating effect thus obtained. If the switch or armature 19 drops sufficiently away from the magnet 18 so that it is not returned when the magnet is .deenergized, the switch may be restored manually or by other control means. Furthermore, under clear condition the armature 20a may be moved away from the path of movement of the inductor so as not to be effective, thereby avoiding the signal impulse so that the armature will not disturb the magnetic condition of the inductor. The movement of the arm ature away from its operative condition is the equivalent otthe closing of the circuit of the choke coil 21 in the apparatus shown in Fig. 1.

Fig. 3 illustrates a direct current apparatus wherein the inductor 7 b has the same core as shown in Figs. 1 and 2. Exciting windings or coils 15b embrace the legs 8 and 9, and are connected in circuit with a battery 16b. The impulse winding or coil 17 b embraces the leg 10 and is connected in circuit with the battery 24 and electromagnet or other translating means 18?). The armature 20 has a choke coil 21 thereon the same as shown in Fig. 1, but the same results may be obtained by moving the armature out of operative position, as described in connection with the armature shown in Fig. 2.

The battery 16?) is of higher voltage than the battery 24, so that the windings 156 are excited to a greater degree than the more weakly excited winding 17?).

lVhen the inductor is away from the armature, the magnetic flux created by the winding's 15?)will flow in the magnetic circuit including the legs 8 and 9, yoke 11 and long air gap between the legs, while the magnetic V flux created by the winding 17?) will flow in the magnetic circuit including the legs 9 and 10, yoke 12 and short air gap between the pole portions 13. The magnetic flux of the two circuits oppose one another. Thus, the magnetic flux created by the windings 15b flows in one direction in the leg 9', while the magnetic flux created by the winding 17b flows in the opposite direction in said leg 9. the

magnetic flux of the winding 17 I) being weaker than that created by the exciting windings 15b. The battery 24 energizes the electro-magnet 18?) to hold the switch or armature 19 raised.

When the inductor passes the armature with the switch 22 open, the armature bridging the long air gap of the core, with a sudden movement, will result in a single cycle of alternating current being induced into the circuit of the winding 17b, and one halt-cycle thereof opposes the current from battery 24, thereby obtaining a neutralizing efi'ect in the winding 17 b, or a counter action tending to retard or reverse the flow of current in the winding 17?). Consequently, the magnet 18?) is deenergized to let the switch or armature 19 drop. If the switch 22 is closed, then the choke coil 21 olfers impedance to the flow of magnetic flux in the armature, so that the magnetic equilibrium of the inductor is not appreciably disturbed, the same as though the armature were not present.

Theinductors and armatures or" the several forms of apparatus shown may be located either longitudinally or transversely of the track or path of movement of the vehicle, and the apparati are shown in their most simple constructions. The present device is for obtaining an initiating or actuating impulse, which is useful in itself, and, if desired, any means well known in the prior art may be used for obtaining a nullifying or restoring efiect.

Having thus described the invention, what is claimed as new is I 1. An inductive control device to transmit an impulse when passing an inert armature in inductive relation therewith, including two magnetic circuits, a constantly energized exciting winding common to both circuits, one magnetic circuit having a long air gap to be magnetically bridged by said armature, the other magnetic circuit having a short air gap, a normally energized impulse winding under the influence of the second named circuit and arranged to be deenergized by the change in magnetic flux in the magnetic circuits when the armature magnetically bridges said long gap, said air gaps being independent of one another so that the bridging of the long air gap by the armature will shunt the secondnamed magnetic circuit, and translating means controlled by said impulse winding to be energized and deenergized therewith.

2. An inductive control device to transmit an impulse when passing an inert armature in inductive relation therewith, including two magnetic circuits having a portion in common to both of them, a constantly energized exciting winding on said portion, one magnetic circuit having a long air gap to be magnetically bridged by said armature, the other magnetic circuit having a short air Eat). a normallv ener ized impulse windin flux :in the magnetic circuits when the armahaving an air gun, a constantly energized ture magnetically bridges said long air gap, said an gaps being independent oi-one an other so that the bridging of the long air gap,

by the armature will shunt the secondn'amed magnetic circuit, and translating means in circuit with said impulse winding tobe ener: gized and deenergized therewith.

3. An inductive controldevice to transmit an impulse when passin an inert armature in inductive relation therewith, including a core having two magnetic? circuit parts each exciting winding common to botn magnetic circuits, the air gap of one magnetic circuit being'relatively long and adapted to he magnetically bridged by the armature, the air gap of tie other magnetic circuit being relatively short, a normally energized impulse winding under the influence of be secondna-med magnetic circuit and-arranged to be deenergized by the change in magnetic flux in the magnetic circuits when the armature magnetically bridges said long air gap, said air gaps being independentof one another so that the bridging o' 'the long air gap by the armature will shunt the secondnamed magnetic circuit, and translatingnieans con trolled by said impulse winding tobe energized and deenergizedtherewith.'

4. An inductive control device to transmit an impulse when passing an inert armature in inductive relation therewith, including a core having two magnetic circuit parts including a portion common to both circuits, and each bridged by the armature, the air gap of the other magnetic circuit being relatively short, a normally energized impulse winding on that part of the core having the short air gap and arranged to be deenergized bythe change in magnetic flux in the magnetic circuits when the armature magnetically bridges said long air gap, and translating means connected in circuit with said impulse winding to be energized, and deenergized with said impulse winding 5. An inductive control device to transmit an impulse when passing an inertarmature in inductive relation therewith, including core having three legs and yokes connecting them providing two magnetic circuits each having an air gap independentof the air gapof the other circuit, with one leg common to'both magnetic circuits, a constantly energized exciting-winding on said leg, the air gap of one magnetic circuit'being relatively long and adapted to be mag netically bridged by the armature, the air gap of the other magnetic circuit being relatively short, arnormally energized impulse winding onithat portioniot the core included in the magnetic circuit having the short air gap and adapted to be deenergized by the change in magnetic flex in the core when the armature magnetically bridgessaid long air gap, andt-ranslatingmeans controlled by said impulse winding to be energized and deenergizedtherewith. 1

6. An inductivecontrol device to transmit an impulse when passing an inert armature in inductive relation therewith, including a core having three legs and yokes connecting them to provide two magnetic circuits each having an air gap independent of the air gap of the other circuit, with one leg common .to both magneticxcircuits, a constantly energized excitin winding on said leg, a normally energized impulse winding on that portion of the core included in one magnetic circuit and arrangedto be deenergized when the armature magnetically bridges the air gaps, and translating means controlled by said impulse winding to be energized and de energized therewith.

7. An inductive control device to transmit an. impulse when passing an inert armature in inductive relation therewith, including two magnetic circuits each having an air gap 7 independent of the air gap of the other circuit, a constantly energized exciting winding common to both circuits, a normally energized impulse winding under theinfluence of one magnetic circuit and arranged to be deenergizedl when "the armature magnetically bridges one of the :air gaps, and translating means controlled by said impulse winding to be energized and deenergized therewith.

8. In combination, an armature, and an inductor movable past said armature in inductive relation therewith and having inductively coupled windings one of which is shunted by said armature.

9. In combination, an armature, an inductor movable past said armature in inductive relation therewith and having inductively coupled windings one of which is shunted by said armature, and translating means controlled by the other winding to be allected when said shunting occurs.

10. In combination, .an armature, and a movable inductor to -move past said armature in inductive relation therewith and having primary andsecondary windings, with the secondary winding arranged to be magnetically shunted when the inductor is in in ductive relation with the armature.

11. In combination, an armature, a movable inductorto move past said armature in inductive relation therewith and having primary and secondarywindings, with th secondary winding arranged to be magnetical- I relation with the armature, and translating means controlled by said secondary winding to be energized and deenergized therewith.

12. In combination, an armature, and an inductor movable past said armature in inductive relation therewith and having primary and secondary windings in inductive relation with reluctance in the magnetic circuit thereof, and the windings being arranged so that said armature, when in inductive relation with the inductor, shunts the secondary winding.

13. In combination, an armature, and an inductor movable past said armature in inductive relation therewith and having primary and secondary windings in inductive relation with reluctance in the magnetic circuit thereof, and the windings being arranged so that said armature, when in inductive relation with the inductor, shunts the secondary winding, and translating means connected in circuit with the secondary winding to be energized and deenergized therewith.

l l. In combination, an armature, and an inductor movable past said armature in inductive relation therewith and having normally energized primary and secondary windings in inductive relation with reluctance in the magnetic circuit thereof, the primary winding being included in another magnetic circuit to be bridged by said armature for shunting the secondary winding to deenergize the secondary winding.

15. A cab carried source of alternating current, a differential inductor designed to be continuously energized by said current and provided with two magnetic paths of respec- 1 tively lesser and greater reluctance, a relay normally held in a predetermined position by flux in the path of lesser reluctance, and a track element designed to decrease the path of greater reluctance when desired and thus change the position of the relay.

16. A cab carried source of alternating current, a differential inductor designed to be continuously energized by said current and provided with twomagnetic paths of respectively lesser and greater reluctance, train control means normally sustained in a predetermined condition by flux in the path of lesser reluctance, and a track element designed to decrease the path of greater reluctance when desired and thus change the con dition of the means.

17. A cab carried source of alternating current, a difierential inductor designed to be continuously energized by said current and provided with two magnetic paths, a first path of normally lesser and a second path of i normally greater reluctance, a relay normalbelow that of the first path when desired and thus operate a cab carried relay.

18. A car element for automatic train control systems comprising, a yoke of magnetic material of a configuration resulting in two partial magnetic circuits, one of which has a lower reluctance than the other, means for constantly supplying alternating flux to said circuits, and means continuously responsive to the relative values of these reluctances.

19. A car element for automatic train control systems comprising, a yoke of magnetic material having two partial magnetic circuits one of which has a lower reluctance than the other, means for continuously supplying alternating flux to said circuits, and means continuously responsive to the relative values of these reluctances.

20. A car element for train control systems comprising a source of alternating current and two partial magnetic circuits of normally diiferent reluctances, both energized from said source.

21. A car element for train control systems comprising a source of alternating current, two partial magnetic circuits of normally difierent reluctances both energized from said source, and means responsive to a change in the relative reluctances of said two magnetic circuits.

22. A car element for receiving inductive influences from the trackway comprising, a member of magnetic material, means for producing an undulating magneto motive force in one part of the member, and means for detecting the respective amounts of resulting flux in two other parts of the member nonsymmetrically placed with relation to said one part.

In testimony whereof I hereunto afiix my signature.

DANIEL HERBERT SCHWEYER. 

